Get iframes, objects and some other overlaid widgets to obey their stacking context at last
(a.k.a, keep flash and iframes *under* dhtml menus). (bug #31121)

Implement CSS2.1 quirk about behavior of overflow and root and body. Now we pass Acid2 according to Opera's standard, but in an actual release version.

Implement selectionStart, selectionEnd, setSelectionRange on textarea and text input tags. They are used by editting buttons in phpBB, various wikis, and by autocompletion packages like
Google suggest. Also fix some bugs in synchronization between rendering tree and the DOM for textareas. (bug #71451, bug #79371, bug #113217, bug #121297,
and bug #109092)

Improved keyboard event support, implementing the API in the latest DOM3 Events working group note. Also improve compatibility with other browsers, and fix a couple of crashers. (bug #120408 and bug #118321)